IUCN threat status:

Brief Summary

Biology

Belugas are highly social animals, and in the summer months thousands of individuals can be seen gathered in estuaries; often females with calves will come together whilst males form large bachelor groups (3). Females are sexually mature at around five years of age, they give birth to a single calf after a gestation period that lasts just over a year (6). Mother and calf have an extremely strong bond, swimming very closely together, and the calf will continue to feed on its mothers milk until well into its second year (3). Belugas are able to dive to depths of over 1,000 metres but spend most of their time on the surface of the water swimming slowly. During winter months it may be necessary for individuals to create breathing holes in the ice, which they can do with their heavy head (7). The flippers are capable of a wide-range of movement and enable belugas to manoeuvre themselves effectively (3). In summer months, large numbers of belugas gather in estuaries in order to moult; they rub themselves on the gravel bed and shed the yellow, withered skin of the previous year to once again become gleaming white (3). Belugas feed on a wide variety of fish, bottom-dwelling invertebrates and worms; most of the prey is found on the seabed and it is thought that the highly flexible lips may be used to suck prey into the mouth (8). Sounds can be used to detect prey; the enlarged melon is an electro-receptor for sounds that are sent out from the nasal passages (3). These whales are thought to live for up to 50 years, killer whales and polar bears prey upon them, and belugas are particularly vulnerable if trapped by the ice (6) (7).